正常大鼠脑在光动力治疗中的损伤阈值

Damage threshold of normal rat brain in photodynamic therapy.

作者信息

Chen Q, Chopp M, Madigan L, Dereski M O, Hetzel F W

机构信息

Research and Development, HealthONE, Denver, CO 80218, USA.

出版信息

Photochem Photobiol. 1996 Jul;64(1):163-7. doi: 10.1111/j.1751-1097.1996.tb02437.x.

DOI:10.1111/j.1751-1097.1996.tb02437.x

PMID:8787009

Abstract

Normal brain tissue response to photodynamic therapy (PDT) must be quantified in order to implement PDT as a treatment of brain neoplasm. We therefore calculated the threshold for PDT-induced tissue necrosis in normal brain using Photofrin (porfimer sodium, Quadralogic Technologies Inc., Vancouver, BC) as the photosensitizer. The absolute light fluence-rate distribution for superficial irradiation and effective attenuation depth were measured in vivo using an invasive optical probe. Photosensitizer uptake in cerebral cortex was measured with chemical extraction and fluorometric analysis. Photodynamic therapy-induced lesion depths at various drug dose levels were measured as a biological end point. The PDT threshold for normal brain necrosis was calculated as in the magnitude of 10(16) photons/cm3. Thus normal rat brain is extremely vulnerable to PDT damage. This suggests that extra precautions must be exercised when PDT is used in brain.

摘要

为了将光动力疗法（PDT）用于脑肿瘤治疗，必须对正常脑组织对光动力疗法的反应进行量化。因此，我们使用Photofrin（卟吩姆钠，Quadralogic Technologies Inc.，温哥华，不列颠哥伦比亚省）作为光敏剂，计算了正常脑组织中光动力疗法诱导组织坏死的阈值。使用侵入性光学探头在体内测量表面照射的绝对光通量率分布和有效衰减深度。通过化学提取和荧光分析测量大脑皮质中光敏剂的摄取量。测量不同药物剂量水平下光动力疗法诱导的病变深度作为生物学终点。正常脑坏死的光动力疗法阈值计算为10(16) 光子/cm³量级。因此，正常大鼠脑极易受到光动力疗法的损伤。这表明在脑部使用光动力疗法时必须格外小心。